New Subsurface Temperature Recorder deployed at XXXXXX label
The NOAA Atlantic Oceanographic and Meteorological Laboratory (AOML) conducts the long-term National Coral Reef Monitoring Program (NCRMP) to track the status and trends of coral reef ecosystems of the U.S. Atlantic and Caribbean coral reef jurisdictions. This FY21 summary brief provides an overview of the most recent survey efforts.
| Transect | 01m | 05m | 15m | 25m | Total |
|---|---|---|---|---|---|
| east | 314,505 | 314,508 | 315,351 | 315,345 | 1,259,709 |
| north | NA | 313,850 | 313,887 | 257,270 | 885,007 |
| south | 231,351 | 315,094 | 315,095 | 315,091 | 1,176,631 |
| west | NA | 314,240 | 314,245 | 314,243 | 942,728 |
Figure 1: Study sites and depths in Dry Tortugas National Park area
Three years of temperature measurements were retrieved and processed from 14 sites (depths). Temperature was measured using SeaBird Electronics Subsurface Temperature Recorders (STR)s that collected data at 5-minute intervals.
Figure 2: Temperature conditions at four transects in St. Croix (east, west, north and south) representing a depth gradient (1m, 5m, 15m and 25m). Data were collected from September 2019 to September 2022. However, STR from north station - 25m stopped recording earlier on February 2022 and STRs from south station - 1m on Nobember 2011.
Temperature values were similar among the transects and depths depths with the lowest temperatures generally occurring in March (mean: 26.56\(^\circ\)C, min: 25.64\(^\circ\)C, max: 28.27\(^\circ\)C) and the the highest temperatures in September (mean: 29.68\(^\circ\)C, min: 27.22\(^\circ\)C, max: 32.11\(^\circ\)C). The south 1m station presented the highest temperature variability and the maximum temperature values recorded in October 2021 (32.16\(^\circ\)C) and September 2020 (32.11\(^\circ\)C) (Fig. 2).
At the North 15m site, Salt River Bay, additional instruments were deployed for a 72-hour diurnal suite that monitored pH, temperature, light and current speed (Fig. 3). The SeaFET pH logger, EcoPAR and Tiltmeter collected measurements at 15-minute intervals.
Figure 3: Salt River Bay (N 15m) diurnal suite monitoring from Sept 5th to Sept 8th. Top panel: pH and temperature from SeaFET. Bottom panel: Photosynthetically Available Radiation (PAR) and current speed from EcoPAR and Tiltmeter. Grey blocks denote night time throughout sequence of the plot. Instruments measured parameters every 15 minutes.
As part of the diurnal suite, discrete water samples were collected at three-hour intervals (n=15) using Subsurface Automatic Samplers (SAS). These samples will be analyzed for Total Alkalinity (TA), Dissolved Inorganic Carbon (DIC), and Spectrophotometric pH (SpecpH). Using these metrics we can get the calculated values for pCO2 and aragonite saturation state. For more information on SAS vist https://www.coral.noaa.gov/accrete/sas/
Submered Automated Samplers (SAS) deployed to collect water samples every 3 hours
At Salt River Bay, 6 transects were established and surveyed in 2019 to obtain carbonate budgets which describe the summation of all processes contributing to calcification and bioerosion on a reef. This metric is used to determine if a reef is in a state of net accretion; growing or net loss; flattening. We revisited this site and recorded the abundance and cover of all major carbonate producing (coral and CCA) and eroding taxa (urchin, bioeroding sponges and parrotfish) to find out the new carbonate budget status after 3 years.
Figure 4: Carbonate budgets Salt River Bay in 2019 and 2022 and the processes contributing to calcification and bioerosion. Carbonate budgets declined in 2022 compared to 2019, mainly due to the reduction in coral production and the increase in urching erosion.
The transect results showed that carbonate budgets have become negative in 2022, which implies that this site has shifted to being net erosional over the past 3 years.
CAU and BMU pair before retreval after being deployed for 3 years. CAUs are 2 parallel PVC plates to quantify settled accretors. BMU is mounted coral skeleton installed at the base of the metal stake and has been encrusted.
Landscape Mosaic collected from transect 6
AOML’s climate monitoring is a key part of the National Coral Reef Monitoring Program of NOAA’s Coral Reef Conservation Program (CRCP), providing integrated, consistent, and comparable data across U.S. Managed coral reef ecosystems. CRCP monitoring efforts aim to:
Atlantic Climate team lead: nicole.besemer@noaa.gov
Principal Investigator: ian.enochs@noaa.gov
NCRMP Coordinator: erica.towle@noaa.gov
Coral Reef Conservation Program: http://coralreef.noaa.gov
NCRMP climate monitoring: https://www.coris.noaa.gov/monitoring/climate.html
NOAA Atlantic Oceanographic and Meteorological Laboratory: http://www.aoml.noaa.gov/
These efforts were jointly funded by NOAA’s CRCP and OAP. We would like to sincerely thank the National Park Service as well as Caribbean Sea Adventures for supporting our field efforts and assisting monitoring surveys
AOMLs NCRMP Atlantic and Caribbean Climate Team: I. Enochs, N. Besemer, G. Kolodziej, M. Chakraborty, A.Boyd, M. Jankulak, A. Palacio-Castro, A. Webb, B. Chomitz